Transmission of sound.



No. 636,5l9. Patented Nov. 7, |899.

E. GRAY & A. J. MUNDY.

TRANSMISSION 0F SOUND.

, (Application med Ap. 14, 1899-) (No Model.) 3 Sheets-Sheet 2.

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" lunumnug w Q IlIIIIH Patented Nov. 7, |899.

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TRANSMISSION 0F SOUND.

(Application leclApr. 14, 1899.)

3 Sheets-Sheet 3.

(No Modell.)

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UNTTR STATRS `PATENT tric.

ELISHA GRAY, ORHIGHLAND PARK, ILLINOIS, AND ARTHUR J. MUNDY, on NEWTON,MASSACHUSETTS.

TRANSIVHSSION OF SOUND.

SPECIFICATION forming part of' Lettere Patent No. 636,519, datedNovember 7, 1899.

Application filed April 14, 1 8 9 9 To @ZZ whom it may concern:

Be it known that we,ELISHA GRAY, of Highland Park, in the County of Lakeand State of Illinois, and ARTHUR J. MUNDY, of Newton,l in the county ofMiddlesex and State of Massachusetts, have invented a new and usefulImprovement in the V.Transmission of Sound, of which the following is afull, clear, and exact description, reference being had to theaccompanying drawings, forming a part of this specification, inexplaining its nature.

Our invention relates to a method of ringing or sounding a bell and alsoto a system and apparatus for transmitting intelligence between ships atsea and between the shore and any ship by means of sound-signals made inthe water at the transmitting-station by electrical means. These soundsare picked up from the water at the receiving-station by means ofelectrical or mechanical devices.Y At present we prefer an electricaldevice, that will be hereinafter described.

Great difficulty is experienced in transmitting signals between ships atsea by the present methods. Visual signals are of no use in time of afog, and sound-signals are not reliable because of the varyingatmospheric conditions that are constantly going on. Sounds that may beheard forV many miles under certain conditions of the atmosphere will beinaudible for one mile under certain other conditions.

Water is a homogeneous body and is not subject to the difficulties thatare met with in the air, the conditions being the same at all times.Further, sound is transmitted through water at about four times thespeed that it is through the air.

Sound-signals may be produced in the water by different methods; but weprefer in our system to use a bell that is rung electrically, butwithout mechanical impactsuch, for instance, as is produced by the blowof a hammer.

By bell7 we desire to be understood as meaning the thing which has beendefined as an open percussion instrument varying in shape and material,but usually cup-like or globular and metallic, so constructed as toyield one dominant note; but we do not use the bell in the way in whichit was designed Serial No. 713,037. (No model.)

to be used, as we do not employ in producing its dominant tone thepercussion of a hammer or tongue, so that by ringing the bell we do notmean to be understood as ringing it in the ordinary and known sense;still for convenience we shall continue to employ that phrase. The bellis rung by subjecting its rim to the direct action of magnetic lines offorce created by electrical means and of a 6o character to impart to thebell the rate of Vibration of its dominant tone. We prefer to obtainthis result by locating electromagnets adjacent to the rim, by mountingwhere necessary pole-pieces on the rim or sound-bow of the bell tocooperate with the electromagnets, and by providing the electromagnetswith an energizing vibrating current of the rate of vi bration of thedominant tone of the bell. Vhile there may be employed for producing 7othis result one electromagnet, for various reasons we prefer to employmagnets arranged in pairs, which pairs are diametrically opposed to eachother with respect to the bell, and to also energize the setsalternately with vibrations or pulsations of the rate of the dominanttone of the bell for reasons hereinafter given. The bell thus employedis put to a new use, and the means for ringing it are also novel. Thecharacter of the sound produced estab- 8o lishes the fact that a newmethod of using the bell and ringing it and a new sound have beendiscovered. The sound which is thus obtained from the bell is of apeculiar nature and varies from sound before obtained from bells in that`it is pure, being substantially free from overtones, in that it is ormay be continuous with respect to volu'me for any desired interval oftime, and in that it may be interrupted and immediately repeated with-9o out varying its volume orintensity. Our method, it may be said, -hasalso this marked distinction from the ordinary ringing of the bell inthat it selects and maintains the dominant tone of the bell freed fromovertones or other tones calculated to muffle or destroy its characteror carrying capacity.r The new tone produced also has, because of itspurity and because of its continuity, remarkable carrying effect, eitherin the water or in the Ioo air, which seems to be of a cumulativenature-that is, its insistence extends the soundtion to the bell of Fig.the electrical conwaves to continuously greater distances from theirsource for a limited period.

The method may be practiced in the air or in the water and at any depthand without any inclosure-to the bell, the bell communicating directlyto the water its sound-vibrationsa'nd forthe period of such vibrations,and itis especially adapted because of this and because of the characterof the sound for use as a means for originating sound-signals either inthe air or in the water, and especially in the latter, and we haverepresentenA as a portionofour invention submerged sound-receivingdevices which are adapted vto take up and transmit the new sounds andwhich will hereinafter be more fully set forth;

Having described the object ofr our invention', we will now proceed to adescription of the apparatus used in carrying it into operation.

Like letters and numerals of reference refer to like parts in thedifferent figures.

In the drawings, Figure l is a view in vertical section of a bell havingmounted within it a system of eleetromagnets b y means of which the bellis caused to ring. Fig. 2 is a View of the bell, looking into it,showing the relation of the magnets, their pole-pieces, and armatures tothe bell itself. Fig. S is a plan View showing the connections betweenthe magnets mounted in the bell and the appa- .ratus for communicatingthe electrical impulses from a source of electricity to the bell. Fig; 4is a front View of one form of an electrical'receiving apparatus. It isintended to pick up the sounds from the water that may be transmitted toit from any distant point. Fig. 5 is an ideal sketch showing a bellimmersed in the water with electrical connections running to a pointabove the water, which are connected with a battery, and an apparatusfor transmitting impulses to the bell for the purpose of ringing it.Fig. 6 is an endv view of the electrical receiver of Fig. 4, showingsubmerged and in operative relanections with the point of interruptionin the center of the receiving-diaphragm and the telephone-receiverabove the water. Figs. 7 and 8 show two other forms of electricalreceivers. Fig. 9 represents a view in section and plan of the vibratorand spring-contacts which connect it with wires hereinafter specied,showing the relation of these parts when the vibrator is at rest. Figs.l0 and ll are similar views representing the relation of the Vibrator tothe springs when in action.

A is a bell, (shown in vertical section,`) having mounted within itmagnets B C D E F G II I. All of these magnets cannot be seen in oneView. They are shown in their relation to each other in the plan-view,Fig. 3. In Fig. 2 four of them are seen-viz., C E G I. Strictlyspeaking, there are only four magnets arranged at right angles to eachother; but there areeight coils, one for each limb of each magnet, andthese coils have independent connections by means of a cable to thetransmitting apparatus above the water. The reason of this will be'given hereinafter. The cores of these magnets are built up fromlaminations cut in the form of a cross from thin soft iron. The magnetsare sustained by a strong steel support J, which passes through thecrown of the bell and is held rmly by a screw threaded on the end ofthis support, which passes through and is held in place by a nut K,having an eye in it for con- Avcnience in the suspension of the bell.This support is held more firmly in position by means of the braces L L.The lower end of the support .I is also threaded and passes through themagnet-cores in the center of the cross, the magnets being held in placeby means of a nut M. The two sets of magnetcores are held apart and intheir proper posit-ion by means of a washer N. The s upport J has ashoulder m on it, so that -when the nut M is turned up the two sets ofmagnets are clamped ilrmly together. In cases where the body of the bellis made of non-magnetic metal it is necessary to attach pole pieces orlugs to the bell in order that the magnets may be able to actuate it.

O O O2 G3 are lugs of soft iron attached to the bell by means of. boltsP, passing through the same and held in place by means of nu ts Q. Theselugs preferably are adjustable and may be arranged to slide back andforth for this purpose on the bolts P and are held in position by meansof screws R' or any other suitable device. These lugs should stand awayfromv the poles of the magnets at a distance that will produce the bestresults, which is determined by'experiment. l In Fig. 3 a plan View isgiven, showing the circuits that connect the magnets of the bell withthe vibrator which transmits the electrical impulses.

S, Fig. 3, is a tuned vibrator mounted securely to a post T, which isrigidly fastened to the base of the instrument. This vibrator isconstructed and operated substantially the saine as the reed shown inpatent to applicant, Elisha Gray, No. 165,728, dated July 20, 1875. Thisvibrator is so tuned that its normal rate of vibration is the same asthe dominant or fundamental note of the bell with which it is connected.If the vibrator is not in exact accord in its rate of vibration withthat of the bell, no sound will be produced, although electricpulsations may be passing through the bell-magnets at their full power.IVhen, however, the two are in accord, a full round musical tone will beproduced in the bell with nearly, if not quite, all the overtoneseliminated, such as are present in great numbers when the bell is struckwith a hammer.

It has been determined by experiment that when a vibrator is vibratingagainst a springpoint at the rate of four hundred and twentysix timesper second only about one-half an ampere of electric current under apressure of one hundred and ten volts will pass through it. This amountof current is not enough to IOO IIO

ring a large bell weighing from one to five hundred pounds sufficientlyloud. A means for overcoming this diliculty has been devised and isshown in Fig. 3. The wires 1 2 3 et connect with the same number ofsprings so situated with relation to the vibrator S that when it is atrest the springs will be in slight contact with the points on thevibrator. In the drawings they are shown separated from the points,which is the appearance they have when the reed is in vibration.

By tracing the wires l 2 3 4E it will be seen that No. l connects withmagnet H, No. 2 with I, No. 3 with D, and No. 4 with E. Passing to theother side of the reed, wires 5 6 7 S are similarly related to thevibrator by means of their respective springs, which connect in the samemanner as heretofore described with the vibrator when at rest. Wires 5 67 8 con nect with the magnets B C F G, which lie at right angles withthe other set. IVhen the Vibrator is in action, it is only connected toone set of springs at a time. For instance, when it swings in thedirection of the arrow at the end of the vibrator the four pointsbelonging to the wires l 2 3 4 are in contact with their respectivesprings and out of contact with the springs on the opposite side of thereed. This will cause electrical impulses to pass simultaneously throughthe wires l 2 3 4 and their corresponding magnets H I D E. Inasmuch aseach of these wires carries a half an ampere of current there will be anaggregate of two amperes passing through this set of magnets. NVhen thevibrator swings to the opposite side, the second set of magnets B C F Gare charged in the same manner because of the contact of the vibratorwith wires 5 6 7 8. The first set of magnets will at the same time bedischarged because they are out of electrical contact with the vibrator.The opposite ends of the wires of all the coils are joined together toone common returnwire 9, which connects with one pole of the source ofelectricity II, the other pole being connected with the vibrator.

A separate battery V may be used to actuate the vibrator S, it beingwell known, of course, that a branch of the same battery which operatesthe bell may be used also to operate the vibrator.

In order that signals may be produced rapn idly, it is necessary thatthe bell should start and stop ringing with promptness. This isaccomplished by causing the current passing through the bell-magnets tochange from a vibratory character to a continuous current. There areseveral methods of accomplishing this, and we do not intend to confineourselves to any one. One method is shown in Fig. 3, which accomplishesthe result very satisfactorily. The vibrator S stops and starts verypromptly by simply making and breaking the circuit, which actuates it bymeans of a key.

NV, Fig. 3, is a key placed in the circuit of the battery V, whichactuates the vibrator S. When the key is depressed, a circuit isestablished from the battery V through the vibrator-magnets S S2, andthe vibrator will then promptly vibrate and continue to do so until thekey is let up again, when the vibrator promptly comes to rest. Asheretofore explained, when the vibrator is at rest all of the eightsprings connecting with the eight sections of the magnet are in contactwith the reed; but when the vibrator is in Vibration only four are incontact at a time. This, however, is accomplished so rapidly that to theeye all of the springs seem to stand away from the vibrator, as shown inthe drawings. When it is desirable to send signals, which may be thelong and short characters of the Morse alphabet, (or any other arbitrarysignals that may be agreed upon,) the operation is as follows: Assumingthat the bell and the vibrator are in exact accord as to their naturalor fundamental rate of vibration, the bell will sound whenever thevibrator is put in vibration if connected with a suitable source ofelectricity. When the key Wis closed, the vibrator is set inA motion andthe bell rings. Vhen it is opened, the vibratoreeases to vibrate and allof the eight springs are in contact with the vibrator. This allows apowerful steady current to pass through all the magnets, which has theeffect to immediately damp the bell, which otherwise would sound formany seconds of time before coming to rest. By this means, however, thecessation of sound is instantaneous, and from the fact that the bell isunder a strain it more promptly starts up when the vibrator S is againput in vibration by depressing the key IV. By this means sharp andstrong signals may be rapidly produced, so that messages are transmittedwith the same facility as by the ordinary Morse telegraph.

If we should take away one set of the springs connected with thereed-forinstance, 5, 6, 7, and S-the bell would still ring when thevibrator acted, but with only about half the power as when the full setof springs is in use. The reason for this may be explained as follows:Then the vibrator is in contact with the springs l 2 3 4, the magnets III D E are energized, and the bell is drawn toward the poles of thesemagnets, causing it to assume an oval shape, which throws it awaycorrespondingly from the poles of the magnets B C F G. l/Vhen thevibrator swings away from the first set of springs, the mag- IIO netscorresponding tothem are denergized drawn in on a line at right angleswith the direction that it was attracted by the first set of springs,thus giving the bell a double irnpulse, one on each half of itsvibration. If

it is desirable to get a greater amount of current into the bell, stillother divisions may be made in the winding of the magnets and a greaternumber of spring-points added to the vibrator, or, if it is moreconvenient, two vibrators may be driven by the same controlling power,each operating in connection with a certain number of spring-points. We

do not mean to limit ourselves to any definite number, but be governedby the necessity of each individual case.

The bell and magnets when used for submarine telegraphy may be submergedin the Water in any desired way. Vith the construction in Fig. 1 it issimply necessary to suspend the bell in the water by means of its eyeand a holding-chain.

The bell may be operated from a battery and operating devices placed atany desired distance from it.

It will be understood that for submarine purposes the bell willgenerally be of large size, varying from two hundred and fifty to twothousand five hundred pounds and upward in weight; also, that themagnets are of corresponding size and force and that the electriccurrent employed must be sufficient to properly energizewith one or morepulsating or vibrating currents the magnets, and we prefer to employ forthe purpose of getting the largest results from the power. used theconstruction represented in Fig. 3 or its equivalent.

It will be understood that the bell is sounded or rung by the vibratoryaction induced in it by the vibrating impulses of the magnets and thatthese vibrations may be continued in the magnets and consequently in thebell for an indefinite period and that the sound produced by the bell isvery different in its tone and in its operative effect upon Water incommunieating signals from a sound which is the re sultant of a singleblow or even a succession of blows.

Having described the construction and operation of the bell and themanner of producing signals, we will now turn our attention to thereceiving instrument.

Fig. Il is one form of an electrotelephonic receiver. X is an iron framehaving stretched Within it a thin iron or steel diaphragm Y. Thisdiaphragm is tirml y secured to the bottom of the frame by means ofscrews and clamps, while at the top it is secured to the bar Z, to whichare attached a number of bolts that project up through the upper part ofthe frame X and are threaded and provided with nuts by which the properstrain may be put upon the diaphragm.

A' is a small box placed upon the center of the diaphragm, which isfastened to it so as to be water-tight. This box is simply a protectionfor a circuit-breaker B', better shown in Fig. 6, which is an end Viewof Fig. 4E. This circuit-breaker is simply a light lever which iselectrically insulated from the diaphragm except at its point where thelever rests on the diaphragm. This lever is so made as to have a rate ofvibration naturally slower th an that of the diaphragm itself whenvibrating under the influence of a sound coming to it from thetransmitter. From this vibrating lever an insulated wire is connectedwhich runs to a point above the water in which the receiver is immersedand connects there with an ordinary receiving-telephone. Another wire,which may or maynot beinsulated, connects with the diaphragm through theframe of the apparatus to the other side of the telephone-receiver. Inthis circuit is placed a small battery which is connected to theinduction-coil of a telephonie receiver in the ordinary way. In order toget the best results from this receiver and to cause it to pick upsounds made in the water at the greatest possible distance, it should betuned by means of the bolts and nuts at the top of the frame until itsnatural rate of vibration isin accord with the bell from which it isreceiving signals. This is not necessary for ordinary distances, as adiaphragm will respond to all pitches of sound, but better to the onefor which it is tuned, it' it is timed at all.

When in operation, the bell is lowered to any given depth in the water,which should be so far down as not to be interfered with by the waves.The receiver should be lowered into the water about the same distance.When a message is to be sent, for instance, between one ship andanother, the bell is lowered into the water, if not already in thatposition, at the transmitting end, while the receiver will be in placeat the receiving end on the other ship. Electrical signals are nowtransmitted to the bell in the manner that we have heretofore described.The sounds created by the bell will be transmitted through the water ata speed about four times as great as it would pass through the air. If areceiver is anywhere within the sphere of its influence, which will bemany miles, more or less, according to the size and power of the bell,the sounds will be picked up by this receiver and reproduced in thereceiving-telephone on board the ships, which may be read and writtendown in the same manner that an operator reads an ordinary Morsemessage. Of course each station is provided with both a transmitter andreceiver.

Two other forms of receivers are shown in Figs. 7 and 8. These differfrom the form just described in that the diaphragm is stretched acrossthe end of a very short drum, which is made water-tight. The connectionwith the IOO IIO

telephone above the water is precisely the qsame as that described forFig. 4.

Fig. 7 shows a lever-contact with the diaphragm mounted in the samemanner as in Fig. 4, except that there is no necessity for a box toprotect it, as it is inside of a chamber. The chamber is provided with acap C for the purpose of opening up the chamber, if necessary. Fig. 8 isa chamber of the same construction, but instead of the lever restingupon the diaphragm an ordinary telephonetransmitter is placed within thedrum and is actuated by the movement of the outer diaphragm moving theair within the inclosed drum, which in turn moves the diaphragm of thetransmitter.

When a sound-wave passing through the water strikes the diaphragm of thereceiver, it moves at a higherl rate of speed than the lever naturallyvibrates, and therefore causes it to jar at its point, which disturbsthe electrical equilibrium of the circuit, causing a sound in thereceiving-telephone. This is a more sensitive receiver than the ordinaryspeaking-telephone would be. It is not necessary for the reception ofinarticulate soundsignals that the receiver be adjusted to takearticulate sounds, but it is much more sensitive when constructed toreceive a sound of a definite pitch. For short-range work, say within aradius of five miles, it is not necessary to construct the receiver tobe thus sensitive.

The wires on shipboard or on shore may be carried to a quiet room on theinside, so that the operator will not be disturbed by eXtraneous sounds.

By the system and method herein described we are enabled toproducesounds or signals by means of a bell which have a special and valuableproperty as distinguished from a sound produced by a blow or successionof blows upon a bell in that the sound which is thus produced is of asustained character, the duration of which may be varied at will. It isof special value as a means for producing signals in water to becommunicated to and carried by water, because such sound vibrations socommunicated to the water by the bell will be so sustained or continuedand even cumulative in eifect that they will have a greater carryingpower in the water than sounds produced in the ordinary way, and whenthis is supplemented by employing in obtaining the sound vibrations ofthe rate necessary for producing the dominant tone or note of the bellthe carrying effect of the sound in the water is further amplified andincreased. Moreover, sustained sound vibrations or sounds thus producedwhen under such con trol as is afforded by the employment of electricityprovide a very desirable means for communicating information orsignals,because in the rst place they can be so readily established ormade by a key or other instrumentality and because their length may beinfinitely varied and in any desired order.

While of course one magnet may be employed for sounding or ringing thebell, we prefer to use two magnets or a multiple of two and to arrangethem back to back or in opposed relation to each other, so that thestress of one will be counteracted by the stress of the other and alsoso that they may simultaneously act upon sections of the belldiametrically opposed to each other. By so acting the body of the bellis held in equilibrium and does not require bracing against the pull ofeither magnet.

The arrangement represented in the drawings where the magnets are insidethe cavity of the bell istherefore a very desirable one, although wewould not be understood as limthe iniiuence of Water by insulation andby copper-plating. For instance, the poles and the pole-pieces when usedwill be copperplated.

The bell if of a copper alloy may or may not be copper-plated. The wirewould of course be insulated.

While we have described the invention as especially useful for thepurpose of communicating submarine signals, we would not be understoodas limiting the method of ringing or sounding the bell to this use, asthis portion of the invention may be used in sounding or ringing thebell under any conditions and in the air as well as in the water.

It will be understood that the electric vibrator makes contact with thewires l to 8 preferably by means of intermediate springs, which are whenthe vibrator is at rest in contact with it at botl1-sides, but whichwhen the vibrator is in motion have short periods when they are not incontact with it. This enables a longer contact to be established du ringeach swing or movement of the vibrator with wires on each side thereof,so that a larger volu me roo of electricity may pass through the wiresbecause of this prolonged contact.

When magnets of the character speciiied are used, we prefer that thepoles of the magnets and the pole-pieces be shaped and ar- 1,05

ranged with relation to each other, as represented in Fig. l.

By our method the bell is rung by the direct action of magnetic lines offorce, created by electrical means, without any mechanical 11o contactwhatever with the bell itself. These lines of force are propagatedthrough the luminiterous ether across the airgaps between the poles ofthe magnets and the armatures or lugs that are rigidly attached to the115 tures attached to it, we much prefer to use 12 5 the latter becausethey can be constructed of iron laminations that will not heat when inaction. It is found that solid iron or steel when used to form any partof the magnetic circuit will become intensely heated under 15o theaction of such powerful currents as We use in ringing a large bell. Bythe use of laminated cores in the magnets and armatures constructed inthe same way this difti- If not used, the magnetic cir- 12o culty isentirely avoided. NVhen the magnetic circuit is established, there is anattraction between the lugs (or walls of the bell, as the case may be)and the poles of the magnets. This partly closes the air-gap between thebell and the magnet-poles, but not enough to allow actual contact. We donot claim ringing a bell indirectly by electrical means, but we do claimringing it directly by electrical meansthat is to say, in the formercase the hammer of the bell is actuated by electrical means; but thebell is as surely rung by mechanical impact between the hammer and thebell as it would be it' the hammer were wielded by a mans arm or by anyother power.

It will be seen that by our method of ringing a bell neither a hammernor anything corresponding to it strikes the bell, and it makes nomechanical cont-act or impact with any substance other than the air orwater (as the case may be) when it rings. It rings by a series ofrythmical magnetic pulls propagated through the ether as lines of force.These pulls have a rate per second corresponding to the dominant note ofthe bell. It is a new art in bell ringing. The old method involves ablow with some sort of hammer against the bell which is actuated'by someextraneous force. This blow causes not only the fundamental note of thebell to sound, but also all its overtones, producing a clang rather thana musical tone. These overtones are many of them discordant and tend tokill or reduce the power of the dominant tone, so that its carryingpoweris very much weakened. Our new method avoids all this. Employing, as wedo, only magnetic lines of force to actuate the bell we are able tosound only the dominant tone, leaving the overtones quiescent. By thismeans a new result is obtained, enabling us to ring any bell much louderand with a purer quality of tone and one that possesses a far greatercarrying power than is'obtained bya bell rung in any of the old ways.Again, this new method enables us to ring a bell in places and in amanner that is not possible with the old methods. For instance, asustained tone of full power can be maintained by our method for anylength of time. This is not possible by the old method. This sustainedtone may be chopped up into long and short sounds representing the Worseor any other code of signals. By our method the bell may be rung underwater at any point or distance from the shore with the same ease as inthe air. This is not possible by any of the old methods. Again, it ispossible by our method to ring the bell very much louder without dangerof breaking it than by the old method which depends upon a blow.

Having thus fully described our invention, we claim and desire to secureby Letters Patent of the United Statesl l. In a bell, means for ringingthe bell by the direct action of magnetic lines of force pulsated at thevibrational rate of the fundamental tone of the bell.

2. A system of submarine telegraphy comprising a submerged bell ot thecharacter specified for communicating signal vibrations or pulsationsdirectly to the water and means for ringing the bell while submerged, bythe direct action of magnetic lines of force pulsated at the vibrationalrate of the fundamental tone of the bell.

3. A bell having two lugs or armatures of magnetic metal rigidlyattached to its sound bow or rim and diametrically opposite each other,and two magnets having their poles in operative relation to said lugs orarmatures, which magnets are energized by an electric current pulsatedat the Vibrational rate of the fundamental tone of the bell.

4. In a system of submarine'telegraphy a submerged bell of the characterspecilied and means for ringing it by the direct action of pulsating orvibrating magnetic lines of force electrically induced of the rate ofvibration of the dominant tone of the bell.

5. In a system of submarine telegraphy a submerged bell of the characterspecified, means for ringing it by the direct action of vibrating orpulsating magnetic lines of force electrically induced having the rateof pulsation or vibration of the dominant tone of the bell, and meansfor varying the length of time of such pulsations or vibrations, as andfor the purposes set forth.

6. A bell having two pairs of lugs or arma-` tures made of magneticmetal rigidly attached to its sound bow or rim at the four quarters, amagnet opposite each lug or armature, having its poles in operativerelation thereto and means for inducing bysaid magnets magnetic lines offorce of the rate of vibration of the dominant tone of the bell.

7. A bell of the character specified submerged in water so that thewater is in direct Contact with its inside and outside surfaces andmeans for subjecting the bell so submerged to the direct action ofmagnetic lines of force pulsated at the vibrational rate of thefundamental tone of the bell.

8. In a system of submarine telegraphy, a bell of the characterspecified, means for ringing it by the direct action of magnetic linesof force pulsated at the vibrational rate of vthe fundamental -tone ofthe bell, and a receiving instrumentality adapted to receive thepulsations or vibrations of the bell.

9. In a system of submarine telegraphy, a submerged bell of thecharacter specified rung by the direct action of magnetic lines of forcepulsated at the vibrational rate of the fundamental tone of the bell,and adapted to communicate its vibrations to the surrounding water,means for varying the length of time of theaction of such magnetic linesof force upon the bell and a submerged receiving instrumentality adaptedto receive the pulsations or vibrations of the water communicated to itby the bell.

IOO

IIO

10. In a system of submarine telegraphy a submerged bell of thecharacter speciiied, means for ringing it by the direct action ofmagnetic lines of force electrically induced without the intervention ofany form of percussion apparatus, and of a character to produce in thebell its dominant tone or note, means for varying the length of time ofsaid action upon the bell, a submerged receiving instrumentality adaptedto receive vibrations of the water communicated to it by the bell andmeans for conducting said vibrations from said receiver to a point moreor less removed from it.

11. The combination of a bell of the character specified, bell-vibratingelectromagnets arranged in proximity to the bell, whereby when energizedthe bell is subjected to the direct action of magnetic lines of forceelectrically induced without the intervention of any form ofpercussionapparatus, a source of electric energy connected with the magnets, andan electric vibrator for producing vibrations in the electric current ofthe fundamental tone of the bell, as and for the purposes set forth.

12. The combination of a bell, bell-vibrating electromagnets arranged inclose proximity to the bell and diametrically opposed to each otherconnected with a source of electric energy and means for simultaneouslyenergizing the said magnets to cause the points of the belldiametrically opposite the magnets to be simultaneously vibrated inopposed directions.

13. A bell, bell-vibratin g electromagnets diametrically oppositelyarranged with respect to each other, to directly act when energized tovibrate the bell, which magnets Yare connected with a source of electricenergy and means for simultaneously energizing the said magnets at thevibrational rate of the fundamental tone of the bell.

14. A bell, bell-vibrating electro magnets to directly act, whenenergized, to vibrate the bell, connected with a source of electricenergy, the said magnets being arranged in two pairs, the members ofeach pair being on the same radial line, and the lines crossing eachother at a right angle, with aA means for simultaneously vibrating eachpair and for alternately vibrating the pairs.

15. A bell, bell-vibrating electromagnets to directly act, whenenergized, to vibrate the bell, connected with a source of electricenergy and arranged in relation to the bell in groups of two,diametrically opposite each other, and an electric vibrator forproducing vibrations in the electric current of the fundamenta-l tone ofthe bell, adapted to induce similar vibrations in the bell-vibratingmagnets, and means for alternately changing the vibrating current fromone pair of magnets to the other.

16. A bell, bell-vibratin g electromagn ets to directly act, whenenergized, to vibrate the bell, the said electromagnets being arrangedto simultaneously act upon the sections ofthe bell diametrically opposedto each other, and

whereby the bell is prevented from being,l

drawn bodily in one direction or the other.

17. A bell, a pair of bell-vibrating electromagnets to directly act,when energized, to vibrate the bell, connected with a source of electricenergy, the said electromagnets being placed back to back within thebell, and being arranged to simultaneously act upon the sections of thebell diametrically opposed to each other, whereby the stress of onemagnet is neutralized by the stress of the other, and whereby also thebell is maintained as a whole in stable position with respect to themagnets.

1S. A bell, bell-vibrating electromagnets to directly act, whenenergized, to vibrate the bell, connected with a source of electricenergy, an electric vibrator capable of producing vibrations in theelectric current of the fundamental tone of the bell, and adapted toinduce similar vibrations in the bell-vibrating magnets, and means forchanging said vibrating current into a continuous current to cause themagnets to act to damp the bell.

19. A bell of the character specified, one or more bell-vibratingelectromagnets in proximity to the bell to exert when energized magneticforce upon the bell to be vibrated, which magnets are connected with asource of eleotric energy and means for producing vibrations in theelectric current, and magnet or magnets of the fundamental tone of thebell, whereby similar vibrations are established in the bell and meansforinitiating and varying the duration of said vibrations.

20. A submerged sound-receiver consisting of a diaphragm strained to adefinite pitch or rate of vibration and so arranged that the water is incontact directly with both its sides.

21. The vibration-receiving instrumentality herein described, submergedin water consisting of a diaphragm having both its surfaces in contactwith the water, adapted to receive vibrations communicated to the water,a circuit-breaker having a natural rate of vibration slower than that ofthe diaphragm itself when vibrating, said breaker being electricallyinsulated excepting at a point resting against the diaphragm, areceiving-telephone and an electric circuit connecting it with thecircuit-breaker and with the diaphragm.

22. The combination of a bell of the character specitied,magnetssuspended in the cavity of the bell opposite the sound bow or rimthereof, connected with a source of electric energy, and having theirpoles adjacent to the sound bow or rim of the bell, pole-pieces carriedby said sound bow or rim of the bell arranged in operative relation tothe poles of the said magnets, said magnets being energized by apulsating current of the vibrational rate of the fundamental tone ofthebell.

23. The combination of a bell of the character specified, four suspendedmagnets ar- IOO ranged with respect to each other and the bell asspecified, and the pole-pieces O, O, O2, O3 attached to the sound bow orrim of the bell and each in operative relation to the poles of one ofthe said magnets, as and for the purposes set forth.

2.4. The combination of the bell and the magnet-cores made of laminatedmetal in the form of a cross, the said magnet-cores being suspended bytheir center in the cavity of the bell, having their poles in operativerelation to the bell.

25. The combination of a bell of the character specified, two pairs ofdiametrically-arranged bellvibrating electromagnets arranged inproximity to the sound bow or rim of the bell and connected With asource of electric energy, an electrovibrator for producing vibrationsin the electric current of the fundamental tone of the bell adapted toinduce similar vibrations in the bell-vibrating magnets and meansconnecting one side of the vibrator with one of said pairs of magnets,and the other side of the vibrator with the other of said pairs ofmagnets, as and for the purposes set forth.

2G. The combination of the bell of the character specified,bell-vibrating electrom aguets in proximity to the sound bow or rim ofthe bell to cause when energized magnetic lines of force which act uponthe bell to vibrate the same, a source of electric energy connected withthe magnets, an electrovibrator capable of producing vibrations in theelectric current of the fundamental tone of the bell and adapted toinduce similar vibrations in the bell-vibrating magnets and meansconnecting each side of the Vibrator with the magnets comprisingyielding contact-points connected with the circuit-Wires and arranged tobel moved by the vibrator during its vibration, whereby a relativelylong contact between the vibrator and contact-points is obtained, as andfor the purposes set forth.

27. The combination of the bell, the bellvibrating electromagnets B, O,D, E, F, G, H, I to directly act, when energized, to vibrate the bell,the battery U connected with the magnets, the vibrator S connected withthe battery, the lines 1,2, 3, 4, 5,6, 7, 8 connected with the magnetsas specified, and arranged upon each side of the vibrator as set forth,the vibrator, magnets and battery and the key W'.

2S. The combination of a bell of the character specified, bell-vibratingelectromagnets arranged in proximity to the sound bow or rim of the belland connected with a source of electric energy, an electrovibrator forproducing vibrations in the electric current of the fundamental tone ofthe bell, adapted to /induce similar vibrationsin the bell-vibratingmagnets, and separate or individual connections between the vibrator andthe magnets, as and for the purposes set forth.

29. In 'a system of submarine telegraphy a submerged bell of thecharacter specified, means for ringing it by the direct action ofmagnetic lines of force electrically induced without the intervention ofany form of percussion apparatus and of a character to produce in thebell its dominant tone or note, means for varying the length of time ofsaid action upon the bell, a submerged receiving instrumentality tunedto the dominant tone or note ot the bell, adapted to receive vibrationsof the water communicated to it bythe bell, and means for conductingsaid vibrations frorn said receiver to a point more or less remote fromit.

ELISI-IA GRAY. ARTHUR J. MUNDY. lVitnesses:

F. F. RAYMOND, 2d, J. M. DOLAN.

